Grinding machine for crank shafts



June 27, 1933.

H. J. ERIKSEN GRINDING MACHINE FOR CRANK SHAFTS Filed Dec. 27, 1930 I INVENTOR $40 java/V [W/fjf I My ATTORNEY Patented June 27 1933 HANS JBGEN EBIKSEN', OI AARHUS, DENHARK enmnme mourns r03 cam sm'rs Application filed December 27, 1930. Serial No. 505,050.

The present invention relates to improveremain in the same position in the bearing.

ments in grinding machines for crank shafts, preferably such crank shafts that have two, four six or more double shafts and which are 5 employed in rapidly rotating engines as for instance automobile engines. The journals of such crank shafts are quickly worn oval, and therefore necessitate a turning or grindto be made cylindrical again.

he clamping of such a crank shaft 1n a lathe requires special tools, which increase the cost of the operation considerably. The grinding of the journals maybe efl'ectuated in a turning lathe or on a specially constructed machine, the first method requiring expensive tools, and the latter special grinding machines.

The machine according to the invention may be produced at a price that allows even smaller workshops to obtain one. It is a well known fact that the smaller workshops usually have no special appliance for grinding crank shaft journals, and for this reason they omit the work even though it be .greatly 5 needed. As furthermore automobiie repairs have to be executed quickly there is no time tosend the crank shaft to a specially equipped for grinding, and when the complamt is shop y bad the crank shaft is renewedat high real -' costs. If, however, a workshop is provided with a gginding machine, the crank shaft may quic 1y be reground at a reasonable cost. The characteristic feature. of the invention is that the crank shaft is clamped in the grinding machine resting on two of its journals, which are in line with each other. These journals lie in two bearings slidably mounted on a slide. The one bearlng carries a grinding disc protruding through an opening in the bearing and rotating in a direction longi-:

The rinding disc is so proportioned that it may ear in upon the crank shaft between the two arms that limit the double crank shaft and is journaled in a system of slides, to allow the adjustment of the grinding stone in several directions in relation to the rotating journal and isclamped in towards this j ournal allowing the grinding off of any uneven portion, leaving t e journal finally precisely round.

Upon this device two, four, six or mor journaled crank-shafts may be ground, as long as two, and two of the journals have a common centre axis, because the two jour nals rotate in two bearings during the grinding process, the one being ground while the other serves to rotate the crank-shaft. I A special device is arranged in the former hear..- ing to prevent a lateral movement of the crank-shaft while being ground.

The invention is illustrated in the accompanying drawing where Fig. 1 is a front elevation of the device,

Fig. 2 a top elevation of-same,

. Fig. 3 a sectional cut through same,

Fig. 4 the hub for the driving cord, Fig. 5 a sectional view of the grinding disc, Fig. 6 a side view of the bearing in which the grinding takes place.

Fig. 7 a side view of the bearing to which the driving means for the crank-shaft are carried, and.

Fig. 8 a top elevation of the bearing shown in Fig. 6.

The machine comprises a base 1 provided in the one side with a long slide 2, carrying two slidablc bearings 3 and 4;. The bearing 3' serves to hold the crank-shaft journal 5, while the bearing. 4 carries the crank-shaft journal 6. The crank-shaft 7 is clamped in position as illustrated in Figs. 1 and 2 in such a manner that the two journals 5 and 6, the centre lines 8 of which are in prolongation of each other and thus common, lie each in a bearing in which they rotate. The one journal 6 carries at the same time a cord pulley b means of which the crank-shaft is rotate whereas the grinding takes place on the other journal.

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The driving power may be taken for instance from an electromotor 9 fitted with pulleys 10 from which a cord 11 is carried over to the other pulleys 12 on the spindle 13 of the grinding disc. This spindle 13 runs in ball bearings it on a vertical slide 15, which by means of a handle 16 journaled at the one end in a post dd, may be adjusted up or down. By means of another slide 17 and handwheel 18 the spindle 13 is adjustable in towards or out from the journal 5, while a third slide 19 with hand-wheel 20 allows the spindle 13 to be adjusted laterally, that is parallel to the longitudinal direction of the journals.

As will be seen trom the drawing particularl Fig. 2 the driving shaft carries a third pul ey 45 which through a cord 46 drives a pulley ll attached to a worm shaft 48 engaging a worm on along shaft 23. In Fig. 1 the worm 2i and the worm wheel 22 are indicated bydotted lines. The shaft 23 is arranged parallel with the slide 2 and is journaled in 'a bearing 2a in the bearin 4:. lit carries a pulley 25 which by means 0 a cord 49 is con' nectcd to a pulley 26 clamped to the journal 6. The cord 49 is continued over a rearwardly projecting pulley 50 rotataby mounted in an arm 531. on the hearing it, to the 'efiect that the cord 49 will endeavour to secure the position of the 'ournal t in its bearing 4.

The details of the constructionapf bearings .3 and i are shown in Figs. ti nd 7. The hearing 3 has an angular cutting 27 in which the journal rests. it is held in position by means of two arms 28 that may be attached to the bearing 3 by means of a stud 29, which clamps together two ball sockets 30, one on each side of each arm, and by this is attained that the arms 28 may be brought to straddle to hold the journal 5 in the bottom of the andil more or less. These arms 28 serve partly gular cutting 2? and partly to abrogate the ateral movement of the crank-shaft, because the arms 28 are pressed out against the jour arms as shown in Fig. 2. Below the journal 5 rests upon a steel block 811, which is clamped to the bearing bymeans of a bolt 32 in an elongated slot 33. thus allowing the steel block 31 to slide forwards and backwards, gliding over two pins 52-. lit may be replaced by another corresponding to the diameter of the crank-shaft journal 5, as these vary in di'derent kinds of motors. The steel block 31 can thus be of varying height and must not project too far forward as shown in Fig. ti. The other bearing t is made in a similar manner. It is provided with an angular cutting 34 for the-journal ti, the angular cutting being provided withtempered steel blocks 35 upon which the journal rotates. Both the bearings 3 and dare made of steel plate and at their lower end cast in one with a slide 36 on the runners 2 on theframe. .The slide 36 and the bearing 4 have each a insi ers screw spindle 39 and hand wheel 40 to be held in any desired position.

la the foregoing it has been mentioned that the crank shaft journals 5 and 6 rotateduring the grinding process. The journal 6 is held down in its hearing by means of the cord 49 as shown in Fig. 7 and described in the foregoing. i

The other bearing 3 is open at front as shown in Fig. emu here the grinding disc all operates. This disc rotates in a direction parallel to the longitudinal direction of the journal, and has in the middle a hollow 42 for a spindle nut lit engaging the spindle 13 as seen in Fig. 5.

The cord pulle 26 isbipartite and gathered by means 0 two clamp screws 52, see Fig. 7. in the hub 53, see Fig. 4 as well, there are inserted three clamp'screws 54 that may be clamped in towards the centre, allowing an adjustment for journals of different diameters. Beside the screw heads there is a scale 55 for adjusting the screw tofit any size of journal for instance it the screws are to clamp a journal of 50 mm. in diameter, the three screws 54 are screwed so far do that their heads are immediately opposite the figure 50' on the scale. The screws thenfit exactly to .this diameter. The two parts of the cord pulley may quickly be clamped to the journal 6 by means of the two screws 52.

The operation of the device is easily understood. lln a. crank-shaft that has been in use some time the journals are worn seewhat oval, and after being ground on the machine are precisely circular.

The two journals with centre line in com-.

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to cover the entire surface of the journa as likewise it is moved up and down by me of the handle it, to allow the hollow inding disc to engage the entire journal for the removal of any projecting parts thereon.

Alter grinding the journals are polished with any suitable means.

The constructive details of the device may i be altered in many difi'erent ways without therefor deviating from the scope of e invention.

Having now described my invention what I claim as new and desire to seen by Let-f ters Patent is:

l. A grinding machine for u shafts. including a slide, two bearings for any two crank shalt journals in alignment adjustable laterally thereon, a rotatable grinding disc protruding through an opening formed in one at said beargs, a spindle the grinding disc, ball bearings fdr this spindle 8. A grinding machine for crank shafts, inarranged in a vertical slide, and a handle cluding two bearings for two of the crank bar for raising or loweringthe grinding disc shaft journals, a rotatable grinding disc and in the slide, at a right angle to the vertical means forrotating the crank shaft, compris- I slide, a horizontal slide, a screw spindle and ing a bipartite pulley to be attached to that '0 handle wheel attached thereto for horizonone of t e two journals which is not being tal adjustment of the grinding disc, means ground each pulley part having projecting for rotating the grinding disc and means for lugs to clamped together by screws, in the rotating the crank shaft in thebearing. hub of the pulley three radiably arranged 10 2. A grinding machine for crank shafts, inadjustment screws to allow the fitting on any 1 eluding a slide, adjustable thereon two bearsize, journals.

ings, for two crank shaft journals a grinding 4- glmding machine for crank shafts, disc operatin through an opening in th 1nclud1ng-ashde,t wo bearin s for two crank one of these arings,,means for adjusting Shaft J Q 'QBJ flfilllstflble &

15 the grinding disc vertically and horizontal able grlndlng disc protrudmg through an no .ly, means for rotating the grinding disc and 9P g h P i ggm a rotatin connection herewith a shaft parallel with g and ll P the g mdlng 1 d th id lid d a worm gearing th means for rotatmg the crank shaft, said bearfor transmitting the rotation from a driving 2 having M 5 3, C p P ES a he engine to the shaft, a pulleybn the shaft en h screw spindle thl'ough 851d clamp 85 gaging a bipartite Pu 1 on the crank h ft pieces and-hand wheel attached to the one journal in the other bearing, a rearwardly arend of an \Screw sPmdle forth? P 'P of clamping the bearings to the slide. ranged galley enga mg the aforesaid pulleys In testimony whereof I have mind y to the e ect of hol ing the crank shaft jour- I nal in its bearin during simultaneous rota mgmture' tion. v r HANS JQlBGEN ERIKSEN.

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